baseimage-tutorial-framework/tfw/internals/networking/server_connector.py

import logging

import zmq
from zmq.eventloop.zmqstream import ZMQStream

from .scope import Scope
from .serialization import serialize_tfw_msg, with_deserialize_tfw_msg

LOG = logging.getLogger(__name__)


class ServerDownlinkConnector:
    def __init__(self, connect_addr):
        self.keys = []
        self._on_recv_callback = None
        self._zmq_sub_socket = zmq.Context.instance().socket(zmq.SUB)
        self._zmq_sub_socket.setsockopt(zmq.RCVHWM, 0)
        self._zmq_sub_socket.connect(connect_addr)
        self._zmq_sub_stream = ZMQStream(self._zmq_sub_socket)

    def subscribe(self, *keys):
        for key in keys:
            self._zmq_sub_socket.setsockopt_string(zmq.SUBSCRIBE, key)
            self.keys.append(key)

    def unsubscribe(self, *keys):
        for key in keys:
            self._zmq_sub_socket.setsockopt_string(zmq.UNSUBSCRIBE, key)
            self.keys.remove(key)

    def register_callback(self, callback):
        self._on_recv_callback = callback
        self._zmq_sub_stream.on_recv(with_deserialize_tfw_msg(self._on_recv))

    def _on_recv(self, message):
        key = message['key']
        if key in self.keys or '' in self.keys:
            self._on_recv_callback(message)

    def close(self):
        self._zmq_sub_stream.close()


class ServerUplinkConnector:
    def __init__(self, connect_addr):
        self._zmq_push_socket = zmq.Context.instance().socket(zmq.PUSH)
        self._zmq_push_socket.setsockopt(zmq.SNDHWM, 0)
        self._zmq_push_socket.connect(connect_addr)

    def send_message(self, message, scope=Scope.ZMQ):
        message['scope'] = scope.value
        self._zmq_push_socket.send_multipart(serialize_tfw_msg(message))

    def close(self):
        self._zmq_push_socket.close()


class ServerConnector(ServerDownlinkConnector, ServerUplinkConnector):
    def __init__(self, downlink_connect_addr, uplink_connect_addr):
        ServerDownlinkConnector.__init__(self, downlink_connect_addr)
        ServerUplinkConnector.__init__(self, uplink_connect_addr)

    def close(self):
        ServerDownlinkConnector.close(self)
        ServerUplinkConnector.close(self)